Golf club head

Abstract

A golf club head of the present invention. A cast head body 31 is constituted by a hollow outer shell. Said hollow outer shell define a top portion 35 , a sole portion 37 , a heel wall 45 , a toe portion 39 and a face opening portion 33 . A shaft securing portion 43 is formed adjacent to the heel wall and extended from the top portion to the sole portion. And a first hollow portion 47 is formed between the shaft securing portion and the heel wall of the head body.

1. A golf club head comprising:
 a cast body constituted by a one-piece unitary homogenous hollow outer shell; 
 said hollow outer shell defining a top portion, a sole portion, a heel wall, a toe portion and a face opening portion to which a face portion is to be fixed; 
 a shaft securing portion formed adjacent to said heel wall and extended from said top portion to said sole portion; and 
 a first hollow portion formed between said shaft securing portion and said heel wall of said head body; 
 a second hollow portion formed between said shaft securing portion and said face portion, 
 wherein said shaft securing portion is formed homogeneously with said hollow outer shell to provide a one-piece, unitary, homogenous body, and 
 wherein said sole portion of said hollow outer shell covers substantially a whole of a bottom of said hollow outer shell. 
 
   
   
     2. A golf club head according to  claim 1 , wherein said hollow outer shell defines a face opening portion, a face portion is fixed to said face opening portion. 
   
   
     3. A golf club head according to  claim 2 , wherein a second hollow portion is formed between said shaft securing portion and said face portion. 
   
   
     4. A golf club head according to  claim 2 , wherein said face portion is formed by forging. 
   
   
     5. A golf club head according to  claim 2 , wherein said face portion is formed by press working of a rolled plate member. 
   
   
     6. A golf club head according to  claim 2 , wherein said head body is formed from αβ-type titanium alloy, and said face  3  portion is formed from β-type titanium alloy. 
   
   
     7. A golf club head according to  claim 1 , wherein a shaft securing hole penetrates said shaft securing portion in a region from said top portion to said sole portion. 
   
   
     8. A golf club head according to  claim 1 , wherein said shaft securing hole of said shaft securing portion has a bottom portion. 
   
   
     9. A golf club head according to  claim 8 , wherein said bottom portion is formed in a same surface of said sole portion of said head body. 
   
   
     10. A golf club head according to  claim 8 , wherein said bottom portion of said shaft securing hole has substantially the same thickness as the thickness of said sole portion. 
   
   
     11. A golf club head according to  claim 1 , wherein said hollow outer shell and said shaft securing portion are integrally molded with each other by precise casting. 
   
   
     12. A golf club head according to  claim 1 , wherein said shaft securing portion is formed into a cylindrical shape from said top portion to said sole portion. 
   
   
     13. A golf club head according to  claim 1 , wherein said first hollow portion is formed such that a clearance of 1 mm to 10 mm is defined between said shaft securing portion and said heel wall. 
   
   
     14. A golf club head according to  claim 1 , wherein said heel wall has a thickness of 0.3 mm to 2 mm. 
   
   
     15. A golf club head according to  claim 1 , wherein a width of said first hollow portion adjacent to said sole portion is wider than a width of said first hollow portion adjacent to said top portion. 
   
   
     16. A golf club according to  claim 1 , wherein as edge is formed between said sole portion and said heel wall at a heel side near said shaft securing portion. 
   
   
     17. A golf club head according to  claim 1 , wherein a first upper end of the inside portion of said toe portion is higher than a second upper end of the inside portion of said heel portion in a cross section passing through an axis of said shaft securing hole and along said face portion. 
   
   
     18. A golf club head according to  claim 1 , wherein a hosel portion is formed at said top portion of said head body by projecting said shaft securing portion from said top portion. 
   
   
     19. A golf club head according to  claim 1 , wherein an upper end portion of said shaft securing portion is provided lower than a top of said top portion. 
   
   
     20. A golf club head according to  claim 1 , wherein said head body is formed from β-type titanium alloy. 
   
   
     21. A golf club head comprising:
 a cast body constituted by a hollow outer shell; 
 said hollow outer shell defining a top portion, a sole portion, a heel wall and a toe portion; 
 a shaft securing portion formed adjacent to said heel wall and extended from said top portion to said sole portion; and 
 a first hollow portion formed between said shaft securing portion and said heel wall of said head body, 
 wherein said shaft securing portion is formed homogeneously with said hollow outer shell to provide a one-piece, unitary, homogenous body, 
 wherein a support portion connects said shaft securing portion and said heel wall. 
 
   
   
     22. A golf club head comprising:
 a head body constituted by a hollow outer shell; and 
 a shaft securing portion, homogeneously formed by casting with a top portion and a sole portion of said hollow outer shell; 
 wherein a hollow portion is provided between said shaft securing portion and a heel portion and between said shaft securing portion and a face portion of said outer shell, and 
 wherein said sole portion of said hollow outer shell covers substantially a whole of a bottom of said hollow outer shell. 
 
   
   
     23. A golf club head according to  claim 22 , wherein a joining hole, for joining said shaft securing portion, is provided with one of said top portion and said sole portion. 
   
   
     24. A golf club head comprising:
 a head body constituted by a hollow outer shell; and 
 a shaft securing portion, homogeneously formed by casting with a top portion and a sole portion of said hollow outer shell; and 
 wherein a hollow portion is provided between said shaft securing portion and a heel portion and between said shaft securing portion and a face portion of said outer shell, and 
 wherein said shaft securing portion includes a shaft securing hole extending into said top portion and said sole portion.